While visible light and microscopy helps physicians diagnose the presence of many diseases such as carcinomas, pre-carcinomas and other tumors and related skin diseases, as well as pathologies of tissue and cell preparations (e.g. Pap smears), identification of the disease state is still subject to ambiguity. Having both visible (or fluorescent) and alternative imaging means overlaid on the same presentation would enable the physician to more accurately diagnose equivocal presentations. Alternatively, physicians or technicians without the specialized expertise in pathology could be enabled to more accurately diagnose diseases without immediate consultation of a specialist. Furthermore, the sub-surface condition of the tissue, hence the extent and nature of the disease, is very difficult to assess by optical means due to the limited penetration depth and lack of contrast. By using an array of near-field probes or antennas, operating either alone or co-located with an imaging array using visible light, the present invention is a tool for diagnosis of disease and its extent, e.g. tumor boundaries, helping to minimize the pain and disfigurement of surgery used to diagnose and treat tumors and other diseases of the skin, helping to diagnose malformed precancerous cells in Pap smears, and helping to distinguish between normal and cancerous cells in general.